1. Field of the Invention
The present invention relates to a drainage structure of a volute horn, and more specifically to a drainage structure of a volute horn arranged to enable efficient drainage from a sound path while maintaining the integrity of the sound.
2. Description of the Related Art
A volute horn utilizes an electromagnet to vibrate a diaphragm. Sound is produced by the vibration of the diaphragm and is adjusted in a resonating unit which forms a volute path along which the sound travels. The travelling sound is transmitted to the outside as a horn sound. Since the resonating unit has a bugle-like opening, it is impossible to completely prevent water, such as rainwater, from entering the sound path, even if the horn is attached so that the opening faces downward. For this reason, as shown in FIG. 7, water collects in the sound path and thereby changes the quality and loudness of the sound. If enough water exists in the sound path, the horn cannot produce any sound.
To overcome such a disadvantage, a drainage hole is formed in the resonating unit. Such a drainage hole, however, causes a decrease in pressure within the sound path. The quality and loudness of the sound markedly change with such a decrease in pressure. Another disadvantage with such an arrangement is that water may enter the sound path through the drainage hole.